Trachylinae
Trachylinae is a subclass of hydrozoans. It is placed at order rank in many older classifications, and limited to contain the Narcomedusae and Trachymedusae. But the Actinulidae, then considered an independent order, and probably also the Limnomedusae which were traditionally placed in the paraphyletic "Hydroida", belong to this group too. It is not entirely clear whether the Limnomedusae and the Trachymedusae as conventionally circumscribed are monophyletic
The freshwater jelly Craspedacusta sowerbyi is a well-known member of the Limnomedusae and might thus belong here.Footnotes
